public void ErasingTwoElementsWithTheSameHashMustWork()
{
var table = new HashTableStuff.HashTable <string, int>(HashTableStuff.StringHashFunctions.SimpleHash);
table.Add("+-", 100);
table.Add("X", 200);
// In order to demonstate that tests are correct
Assert.AreEqual(
HashTableStuff.StringHashFunctions.SimpleHash("+-"),
HashTableStuff.StringHashFunctions.SimpleHash("X"));
const double epsilon = 1e-5;
table.Erase("+-");
Assert.IsTrue(table.FillFactor > epsilon);
table.Erase("X");
Assert.IsTrue(table.FillFactor < epsilon);
}
public void ElementEraseMustWorkOnSingleElement()
{
var table = new HashTableStuff.HashTable <string, object>();
table["testproba"] = new object();
table.Erase("testproba");
const double epsilon = 1e-5;
Assert.IsTrue(table.FillFactor < epsilon);
}
public void AddingAndErasingMultipleElementsMustWork()
{
var table = new HashTableStuff.HashTable <string, int>();
for (int i = -10000; i <= 10000; ++i)
{
table.Add(i.ToString(), i - 100);
}
for (int i = -10000; i <= 10000; ++i)
{
Assert.IsTrue(table.IsInTable(i.ToString()));
table.Erase(i.ToString());
}
Assert.AreEqual(0, table.FillFactor, 1e-5);
}
public static void Main(string[] args)
{
PrintProgramName();
var hashFunction = ChooseHashFunction();
PrintHelp();
var hashTable = new HashTableStuff.HashTable <string, int>(hashFunction);
while (true)
{
Console.Write("Enter command: ");
if (!int.TryParse(Console.ReadLine(), out int currentCommand))
{
Console.WriteLine("Invalid command!");
PrintHelp();
}
if (!HashTableHelp.HelpCommands.IsDefined(typeof(HashTableHelp.HelpCommands), currentCommand))
{
Console.WriteLine("Invalid command!");
PrintHelp();
}
else
{
switch ((HashTableHelp.HelpCommands)currentCommand)
{
case HashTableHelp.HelpCommands.ExitProgram:
Console.WriteLine("Good bye!");
return;
case HashTableHelp.HelpCommands.CheckInTable:
Console.Write("Enter key to check: ");
var checkKey = Console.ReadLine();
Console.WriteLine(hashTable.IsInTable(checkKey) ? "In table" : "Not in table");
break;
case HashTableHelp.HelpCommands.InsertElement:
Console.Write("Enter key to insert (or modify): ");
var insertKey = Console.ReadLine();
Console.Write($"Enter new value of table[\"{insertKey}\"] (int): ");
var insertValue = int.Parse(Console.ReadLine());
hashTable[insertKey] = insertValue;
break;
case HashTableHelp.HelpCommands.EraseElement:
Console.Write("Enter key to erase: ");
var eraseKey = Console.ReadLine();
hashTable.Erase(eraseKey);
break;
case HashTableHelp.HelpCommands.Factor:
Console.WriteLine($"Fill factor == {hashTable.FillFactor}");
break;
default:
PrintHelp();
break;
}
}
}
}
public void ErasingNonexistentElementShouldCauseException()
{
var table = new HashTableStuff.HashTable <string, object>();
table.Erase("blahblah");
}